I want to build a metal box that contains a mobile dual band unit, possibly a low power am/fm radio, and also have a 12v aux jack. I plan to have a home setup that in an emergency, i could pack up my antenna, and essentially just unplug a couple things and put a cover over the front of the box and you pick up and go. The primary power i would like to be a 12v power supply so that at home i can just run on 110v. however i would like a high amp switch to be able to swap to running off a car battery with built in leads.

I have all the antenna business and the welding and all that figured out...its the damn power requirements i cant wrap my head around. wha t kind of power supply would i want to run something like this? please feel free to fire off questions, ill try to have a drawing up in a min...

First, get a switching power supply, probably around 20 amps (yes, a bit much--but for the requirement of the aux. 12v tap) and instead of using a high-amp switch, use Anderson power pole connectors. Possibly the Samlex SEC1223 would suit the purpose--or its equivalent. The reason I specify a switching supply is the weight of a regular power supply--if you needed to cart it around.

Just my preference, but I'd set it up so that the power supply would be outside--so you wouldn't have to have it there if you didn't need it, that's where the powerpole connectors come in. One connector on the pigtail out of your box, one connector on the power supply output leads and one connector on your battery.

You could also set it up so that you could use a connector cord right out of your vehicle with powerpole connectors on both ends of it. That cord should use ten gauge wire, the others could use no smaller than twelve gauge--ten would be better.

This is a VERY good point. I've got some inline fuse holders with powerpoles on each end; it's easy to pop them in line any time I'm doing a new hookup. And I have them on any radio gear that doesn't have its own power-line fusing. You can see the fuses in the back right of this photo of my portable QRP station:

First, get a switching power supply, probably around 20 amps (yes, a bit much--but for the requirement of the aux. 12v tap) and instead of using a high-amp switch, use Anderson power pole connectors. Possibly the Samlex SEC1223 would suit the purpose--or its equivalent. The reason I specify a switching supply is the weight of a regular power supply--if you needed to cart it around.

Just my preference, but I'd set it up so that the power supply would be outside--so you wouldn't have to have it there if you didn't need it, that's where the powerpole connectors come in. One connector on the pigtail out of your box, one connector on the power supply output leads and one connector on your battery.

You could also set it up so that you could use a connector cord right out of your vehicle with powerpole connectors on both ends of it. That cord should use ten gauge wire, the others could use no smaller than twelve gauge--ten would be better.

First, thank you very much for everyones input!!

Wow i was thinking even higher for the powersupply...like a 50A...haha and actually a major detail that was left out is the first stop of the mail power will be to a water tight fuse panel. The reason for the powersupply being internal is that in an ideal situation i would also take the box camping with me and we would run it off a generator. And im just a neat freak and want it to be internal haha.

The plan was to use power pole connectors however just have a socket on the back of the box and have a pig tail made for my car.

power poles are good but the other day I saw a battery box (plastic) with cover and it had a gel sell sealed battery in it And both a power gate and a distribution panel mounted on the front. the thing is plugged into 12 volts at home and the powergate keeps the battery charged, so you can charge it from a car or a 12 v power supply. add a second box with a radio, roll up j pole and you are ready to go.

Yes, get a 20 A switching power supply. Maybe a rigged old PC power supply would work great. Should be able to find one for cheap on ebay. Yes, make it external to your mobile case, for the reason noted above.

For the battery, get a deep cycle marine battery. Regular car batteries cannot be deeply discharged without damaging them; I learned this from charging R/C car batteries from one. Regular car batteries are designed to provide high current for a couple starts, but then continually be topped off when you drive away.

Remember not only to get properly sized (amp-wise) fuses, but also use automotive fuses that are rated for DC. Glass or ceramic AC-rated cartridge fuses may or may not break the high DC current under fault condition. These are easy to find at Home Depot, etc. Then, quick-connectors are pretty easy to find too.

Now, you have me thinking about something like this for my first rig getting back into 2m instead of an HT...

Logged

Jeremy (KC9ZHE)*************"America will never be destroyed from the outside. If we falter and lose our freedoms, it will be because we destroyed ourselves."-Abraham Lincoln

Due to the possibility of a second one of these units being needed, and its intended purpose, the power supplies (yes we have upgraded to two). The second one of these boxes will house two dual banders, 10 verizon ptt, HAVE ITS OWN 110V POWER (will be powered by two deep cycle batteries) and will have a laptop mount on top of it.

Don't forget about heat/ventilation. Leave some "air space" and vents or an open top and bottom or fan. Heat kills electronics and all the stuff you mention generates dome. You may have it sitting on a picnic table in the sun, in a smaller none AC space, wherever.

Don't forget about heat/ventilation. Leave some "air space" and vents or an open top and bottom or fan. Heat kills electronics and all the stuff you mention generates dome. You may have it sitting on a picnic table in the sun, in a smaller none AC space, wherever.

Oh we haven't. Two intake fans on the lower front and two exhaust fans upper rear.

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